Arrangement at feed collet

ABSTRACT

In a feed collet for use in automatic machines the arrangement of a sleeve to prevent scratches in the material to be worked and rendering it possible to use one and the same feed collet for several material dimensions.

United States Patent- Svensson Mar. 21, 1972 [54] ARRANGEMENT AT FEEDCOLLET [56] References Cited [72] Inventor: Karl Henning Svensson, 69Stamgatan, UNITED STATES PATENTS Alvsjo, Sweden 2,695,787 11/1954 Sunnen..279/46 1 Flledi Oct 29, 1969 3,41 1,796 11/1968 Decker ..279/46 [2]]Appl. No.2 872,101

Primary Examiner-Andrew R. Juhasz Assistant Examiner-James F. Coan [30]Foreign Appllcatlon Prlorlty Data Atmmey Darby & Darby Oct. 3], 1968Sweden ..l476l/68 [57] ABSTRACT 521 US. Cl... ..279 s1 [5 1] In. C] D D1323b 31/12 In a feed collet for use 1n automatlc machines thearrangement 58 Field of Search ..279/41, 43, 46, 51 0f a sleeve Preve"tniches in 'mateflal m be wmked and rendering it possible to use one andthe same feed collet for several material dimensions.

6 Claims, 6 Drawing Figures Patehtgd March 21, 1912 3,650,538

INVENTOR KARL HENNING SVENSSON ATTORNEYS ARRANGEMENT AT FEED COLLET Inconnection with the working of rod material in automatic machines, forexample automatic lathes, the rod material during its feed at times isscratched by the feed collets. For avoiding such scratches, among othermeasures two sleeve halves of a comparatively soft material have beenfastened by soldering directly in front of each other within a feedcollet. Owing to their gradual wear, however, the sleeve halves had tobe replaced by new ones, which involved time-consuming work for removingthe worn sleeve halves and mounting the new ones. Moreover, for everydimension of rod material a feed collet with soldered-on sleeve halveswas required.

These problems are eliminated by the arrangement according to theinvention, which is characterized in that it comprises a resilientsleeve disposed within the feed collet and adapted to be clampedtogether, which sleeve in its active state embraces the rod material tobe worked and is provided with means to prevent its motion in axialdirection relative to the feed collet during the feed motion of thelatter. Said arrangement is mounted easily detachable in a feed colletand allows for the use of one and the same feed collet for a pluralityof rod dimensions.

The invention is described in greater detail in the following by way ofsome embodiments, with reference to the accompanying drawing in whichFIG. 1 shows an arrangement according to the invention inserted in afeed collet,

FIG. 2 shows an end view of the arrangement in Fig. 1,

FIG. 3 shows another embodiment of the arrangement,

FIG. 4 shows still another embodiment thereof,

FIG. 5 shows an arrangement according to the invention for a hexagonalfeed collet, and

FIG. 6 shows an end view of the sleeve in FIG. 5.

In FIG. I (a portion of) a feed collet l of standard design is shown inwhich an insert sleeve 2 according to the invention is mounted. Saidsleeve 2 is a rotary body provided with a narrower portion 4 of such adiameter that in inserted state of the sleeve in the collet saidnarrower portion abuts to the inside surface of the collet which atnormal use embraces the rod material. The shoulder 5 disposed betweenthe portions 3 and 4 prevents by striking against an inside shoulder 13provided in the feed collet the insert sleeve from moving ahead relativeto the collet at the rearward motion of the latter. The sleeveterminates forwardly in feed direction (to the left in Fig. 1) with aflange 6 of such a diameter that the sleeve can be introduced into thefeed collet from behind and that the flange in inserted state of thesleeve in the collet embraces the forward edges of the collet andthereby prevents the rearward motion of the sleeve.

The sleeve 2 is provided with an axial through hole 7 of substantiallythe same diameter as the rod material to be worked. Two slots 8 arearranged diametrically opposed along the sleeve so as to extend throughthe flange 6 and the narrower portion 4 substantially to the portion 3of greater diameter. Said slots render the sleeve adapted for beingclamped together and thereby to retain a rod work-piece. Two screws 9arranged radially in holes in the sleeve portion 3 of greater diameterand with their heads received in a longitudinal slot in the feed colletare adapted to take along the sleeve in the rotation of the feed collet.

In order to prevent rearward motion of the sleeve in the feed collet,instead of the flange 6 in the wider portion 3 of the sleeve anadditional screw 10 (FIG. 3) can be provided at such a distance from theshoulder 5 that the screw-head abuts to the rear edge ofthe longitudinalslot.

A further possibility of preventing rearward sleeve motion is byproviding its slotted narrower portion 4 with a groove 11 (FIG. 4) for astop ring 12 or the like, said groove being so disposed that the stopring will abut to the forward edge of the feed collet.

For its application together with a hexagonal feed collet, the insertsleeve may have the design as shown in FIGS. 5 and 6, in which case noscrew or the like is required because the sleeve is taken along alone byits external shape.

The insert sleeve according to the invention ls applied in the legs ofthe feed collet are widened and the slotted portion of the sleeve isclamped together. The sleeve having assumed its correct position, theslotted portion springs out and the flange 6 embraces the forward edgeof the feed collet. At the embodiment according to FIG. 3 the screw 10or, at the embodiment according to FIG. 5 the stop ring 12 may beattached for preventing rearward motion of the sleeve in the feedcollet, respectively.

When during the feed motion the feed collet is clamped together, alsothe insert sleeve is clamped together so as to embrace the rod materialand, thereby, take it along in feed direction. When the feed colletafter completed feed releases the sleeve, the slotted sleeve portionsprings out so that the sleeve together with the feed collet can bereturned for a new feed motion.

One essential advantage of the arrangement is that one and the same feedcollet can be used for a plurality of rod dimensions. This is achievedby utilizing a plurality of sleeves with the same outer diametercorresponding to the nominal diameter of the collet, but with differentinner diameters. A 15 mm. feed collet, for example, together with aplurality of sleeves can be utilized for rod material having innerdiameters between 4 and I0 mm.

The insert sleeve according to the invention preferably is made of amaterial, for example phosphor bronze, which is softer than the materialto be worked.

I claim:

1. Arrangement at feed collet for preventing scratches in rod materialin automatic lathes which comprises a resilient sleeve disposed with thefeed collet comprising a forward portion having a relatively smalldiameter abutting the inside diameter of the corresponding feed colletportion and a rear portion having a relatively large diameter incomparison to the forward portion, the sleeve having two parallellongitudinal slots therein extending from the forward portionsubstantially toward the rear portion and adapted to be clampedtogether, a flanged stop ring on the forward portion of the sleeve, saidflanged stop ring having a greater diameter than the forward portion ofthe sleeve and striking against the forward edge of the feed collet toprevent rearward motion of the sleeve relative to the feed collet, onlythe end adjacent the stop ring of the forward portion of the sleeve inits active state embraces the rod material to be worked.

2. Arrangement according to claim 1 wherein the rear portion of thesleeve includes a sleeve shoulder adapted to strike against a shoulderin the feed collet to prevent forward motion of the sleeve relative tothe feed collet.

3. Arrangement according to claim 2 wherein the sleeve includes meansfor connecting the sleeve to rotate with the feed collet.

4. Arrangement according to claim 3, wherein the means for connectingthe sleeve to rotate with the feed collet comprises at least oneradially located fastening device on the rear portion of said sleeve,said fastening device adapted to be received in a correspondinglongitudinal slot in the feed collet.

5. Arrangement according to claim 2 wherein the sleeve has a crosssection in the form of a regular hexagon, and the feed collet has acorresponding inner cross section.

6. Arrangement according to claim 4 wherein the sleeve is comprised of aphosphor bronze which is softer than the material to be worked.

1. Arrangement at feed collet for preventing scratches in rod materialin automatic lathes which comprises a resilient sleeve disposed with thefeed collet comprising a forward portion having a relatively smalldiameter abutting the inside diameter of the corresponding feed colletportion and a rear portion having a relatively large diameter incomparison to the forward portion, the sleeve having two parallellongitudinal slots therein extending from the forward portionsubstantially toward the rear portion and adapted to be clampedtogether, a flanged stop ring on the forward portion of the sleeve, saidflanged stop ring having a greater diameter than the forward portion ofthe sleeve and striking against the forward edge of the feed collet toprevent rearward motion of the sleeve relative to the feed collet, onlythe end adjacent the stop ring of the forward portion of the sleeve inits active state embraces the rod material to be worked.
 2. Arrangementaccording to claim 1 wherein the rear portion of the sleeve includes asleeve shoulder adapted to strike against a shoulder in the feed colletto prevent forward motion of the sleeve relative to the feed collet. 3.Arrangement according to claim 2 wherein the sleeve includes means forconnecting the sleeve to rotate with the feed collet.
 4. Arrangementaccording to claim 3, wherein the means for connecting the sleeve torotate with the feed cOllet comprises at least one radially locatedfastening device on the rear portion of said sleeve, said fasteningdevice adapted to be received in a corresponding longitudinal slot inthe feed collet.
 5. Arrangement according to claim 2 wherein the sleevehas a cross section in the form of a regular hexagon, and the feedcollet has a corresponding inner cross section.
 6. Arrangement accordingto claim 4 wherein the sleeve is comprised of a phosphor bronze which issofter than the material to be worked.